CN212247101U

CN212247101U - Vaporization cooling flue of melting reduction furnace

Info

Publication number: CN212247101U
Application number: CN202020394199.1U
Authority: CN
Inventors: 付玉存; 徐涛; 周海川; 吴玉峰; 任俊; 昝智; 程鹏
Original assignee: Inner Mongolia Saisipu Technology Co ltd
Current assignee: Inner Mongolia Saisipu Technology Co ltd
Priority date: 2020-03-25
Filing date: 2020-03-25
Publication date: 2020-12-29
Anticipated expiration: 2030-03-25

Abstract

The utility model discloses a melting reduction furnace vaporization cooling flue, vaporization cooling flue includes furnace mouth section (1), I section (2) of flue, II sections (3) of flue, III sections (4) of flue, IV section of flue (5), and the vaporization cooling flue cross-section is circular, and the wall thickness of flue wall pipe is 10 ~ 50mm, and the internal and external surface of flue scribbles rust-resistant priming paint, furnace mouth section and I section inner wall of flue knot refractory material (6), I section of flue, II sections of flue, III sections of flue and IV section of flue erode position spraying abrasion-resistant alloy (10) at the inner wall flue gas, and flue pipeline surface is equipped with heat preservation (12). The utility model discloses a vaporization cooling flue has effectively solved the difficult problem of smelting reduction furnace coal gas recycle, has sealed tight not revealing coal gas, can continuous operation, long service life's characteristics.

Description

Vaporization cooling flue of melting reduction furnace

Technical Field

The utility model belongs to the technical field of the iron ore powder heating is reduction in advance, concretely relates to vaporization cooling flue, especially a long-life melting reduction furnace vaporization cooling flue.

Background

The evaporative cooling flue is widely applied to waste heat recovery in the steelmaking production process in the metallurgical industry, and is one of key devices of the steelmaking process. The high-temperature flue gas passes through the vaporization cooling flue, and the high-temperature flue gas transfers the heat energy of the high-temperature flue gas to the heating surface for cooling due to the lower temperature of the heating surface. The water in the heating surface pipe is partially evaporated due to the absorption of the heat energy of the flue gas, and steam is generated. The evaporative cooling is that the heat absorbed by the cooling water is used for self evaporation, and the latent heat of vaporization of the water is used for carrying away the heat of the cooling part. Meanwhile, because water is continuously circulated in the heating surface pipe, the heating surface is cooled, and the metal is not overheated. The converter vaporization cooling flue can not only reduce the exhaust gas temperature and recover the waste heat in the high-temperature flue gas, but also capture part of smoke dust in the flue gas, reduce the content of the smoke dust, ensure the normal operation of the whole steelmaking process system, and simultaneously create conditions for the recovery of combustible gas in the subsequent process.

The evaporation cooling flue is adopted, so that the purpose of cooling flue gas can be achieved, steam can be produced to recover heat, and the energy-saving cooling mode is realized. Although the internal structure of the vaporization cooling flue is relatively simple, the vaporization cooling flue relates to physical phenomena such as combustion, mass transfer, heat transfer, slag bonding and the like, and has severe and complex working conditions and high requirements on design, structure, manufacture, use and the like of equipment. Along with the steep rise and the steep fall of the temperature of the flue gas, the flue can expand and contract, and the flue is difficult to withstand the long-time thermal fatigue effect. This also relates to the stable operation of steel production, so how to guarantee and prolong the life of flue is especially important.

The temperature of the flue gas at the inlet of the vaporization cooling flue for converter steelmaking is very high, generally reaches more than 1500 ℃, compared with converter steelmaking, the temperature of the coal gas generated by the melting reduction furnace is higher, and is between 1600 ℃ and 1700 ℃, and the gasification furnace has the characteristics of large gas quantity, high heat value, high temperature, high pressure and the like. The high-temperature flue gas in the flue also contains a large amount of dust particles, and can generate strong abrasion action on the inner wall of the flue in the process of high-speed movement of the airflow. Therefore, if no measures are taken to protect the inner wall of the flue, the inner side pipe wall can be thinned over time until the flue is failed and scrapped. The gas pressure of the converter is 20Pa, the gas pressure of the smelting reduction furnace is 60-85 KPa, and the pressure is 3000 times that of the converter. Certain smoke dust is also attached to the top gas, and the smoke gas contains a large amount of Fe₂O₃The metal oxides are easy to adhere to the pipe wall of the heating surface and difficult to clean, and the slag bonding gradually spreads along the smoke flow direction and gradually increases along with the extension of the working time of the vaporization cooling flue. Therefore, how to prolong the service life of the gasification cooling flue of the smelting reduction furnace is a problem to be solved urgently at present.

SUMMERY OF THE UTILITY MODEL

In order to achieve the above object, the utility model provides a following technical scheme:

a vaporization cooling flue of a melting reduction furnace comprises a furnace mouth section, a flue I section, a flue II section, a flue III section and a flue IV section. The section of the evaporative cooling flue is circular, the diameter of a pitch circle is phi 4014, the wall thickness of a pipe on the wall surface of the flue is 10-50 mm, and the inner surface and the outer surface of the flue need to be coated with anti-corrosive primer twice. Wherein, the furnace mouth section, the first flue section, the second flue section and the third flue section adopt forced circulation vaporization cooling. The section IV of the flue is in natural circulation but can also realize forced circulation vaporization cooling. And a coal gas outlet of the melting reduction furnace is connected with an inlet of the furnace mouth section, and an outlet of the IV section of the flue is connected with the settling chamber. The furnace mouth section is connected with the melting reduction furnace, the first flue section is connected with the second flue section through metal expansion joints, the fourth flue section is connected with the settling chamber through metal expansion joints, the metal expansion joints counteract thermal expansion and guarantee sealing tightness, and the furnace mouth section is connected with the first flue section through flanges. Two pressure measuring points are additionally arranged on the ascending section of the flue, and one pressure measuring point is additionally arranged on the descending section of the flue and used for tracking and measuring the pressure of the flue.

Furthermore, the inner walls of the furnace mouth section and the first flue section are knotted with refractory materials, phosphate-based binders are adopted, the refractory temperature is over 1700 ℃, the thickness is 50-100 mm, and the lining is fixed by adopting anchoring parts and is used for supporting and fixing the refractory castable of a thinner lining body.

Furthermore, wear-resistant alloy is sprayed on the flue gas scouring parts of the first section of the flue, the second section of the flue, the third section of the flue and the fourth section of the flue. The Al-Si-Fe alloy wear-resistant coating is thermally sprayed, so that the surface performance is improved on the basis of keeping the excellent service performance of the matrix, and the service life of a flue is prolonged.

Furthermore, the flue pipeline is provided with a heat insulation layer, heat insulation is needed when the surface temperature of the flue is higher than 50 ℃, the main heat insulation material adopts rock wool products, and the protective layer adopts galvanized iron sheets.

Furthermore, the flue adopts automatic welding of the membrane wall, the structure is a sealed water-cooled wall formed by a membrane wall tube panel structure, and high-temperature flue gas of the hearth is not directly contacted with the furnace wall, so that slagging is favorably prevented.

Furthermore, because the gas pressure of the smelting reduction furnace is far greater than that of the converter, two bleeding valves are additionally arranged on the III section of the flue and used for pressure relief of flue gas.

Furthermore, the first section and the second section of the flue are cooled separately, so that the water flow of a flue cooling pipe is improved, the cooling effect is improved, and the service life of the flue is prolonged.

Furthermore, natural circulation is adopted in the IV section of the flue to strengthen water making circulation, the volume of the vaporization cooling flue is reduced, and the compact structure is favorable for settling of smoke dust and vibration to remove ash.

Furthermore, the first section of the flue and the second section of the flue are provided with manholes for people to enter and exit equipment so as to facilitate installation, maintenance and safety inspection.

Compared with the prior art, the beneficial effects of the utility model are that:

the utility model discloses to producing a large amount of high temperature coal gas in the smelting reduction furnace production process, having retrieved the energy through the evaporation cooling flue, both rationally utilized the energy, reduced product cost again. The coal gas cooling system adopts a composite circulating cooling mode combining forced circulating evaporative cooling and natural circulating evaporative cooling. The composite circulation cooling mode has the advantages of steam recovery, safety, reliability, long service life and the like. And (3) knotting refractory materials on the inner walls of the furnace mouth section and the first flue section, and spraying wear-resistant alloy on flue gas scouring positions of the first flue section, the second flue section, the third flue section and the fourth flue section so as to prevent scouring abrasion of coal gas flow. The furnace mouth section and the smelting reduction furnace, the first flue section and the second flue section, and the fourth flue section and the settling chamber are connected by metal expansion joints, and the rest parts are connected by flanges, so that the sealing tightness is ensured while the thermal expansion is counteracted, and the deformation or damage of the pipeline caused by thermal elongation or temperature stress can be reduced. The integral tube panel formed by welding the finned tubes together has good air tightness, the outer side of the tube panel only needs to be coated with a thin heat-insulating material, the high-temperature flue gas of the hearth is not in direct contact with a furnace wall, slag bonding is prevented favorably, the tube panel can be manufactured in a manufacturing plant in a sheet mode, and field installation is facilitated. Two bleeding valves are additionally arranged on the III section of the flue and used for pressure relief of the flue gas. The first section of the flue and the second section of the flue are provided with manholes for people to enter and exit the equipment so as to be convenient for installation, maintenance and safety inspection. The utility model discloses not only make full use of the physical sensible heat of high temperature coal gas, prolonged equipment life moreover, realized energy saving and consumption reduction and reduction in production cost's purpose.

Drawings

Fig. 1 is a schematic structural view of a vaporization cooling flue of a novel long-life smelting reduction furnace.

Wherein: 1-a furnace mouth section; 2-flue I section; 3-flue II section; 4-flue III section; 5-IV section of flue; 6-refractory material; 7-a flange; 8-an expansion joint; 9-a manhole; 10-a wear resistant alloy; 11-a bleed valve; 12-an insulating layer; 13-a spring support; 14-measuring the smoke pressure; 15-guide support.

Detailed Description

The technical solutions in the embodiments of the present invention will be described clearly and completely with reference to the accompanying drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art without creative work belong to the protection scope of the present invention.

The utility model provides a melting reduction furnace vaporization cooling flue, vaporization cooling flue includes furnace mouth section (1), I section (2) of flue, II section (3) of flue, III sections (4) of flue, IV section (5) of flue, and the vaporization cooling flue cross-section is circular, and the wall thickness of flue wall pipe is 10 ~ 50mm, and the interior external surface of flue scribbles anti-rust primer, furnace mouth section and I section inner wall of flue knot refractory material (6), I section of flue, II section of flue, III sections of flue and IV section of flue are at inner wall flue gas erosion position spraying abrasion-resistant alloy (10), and flue pipeline surface is equipped with heat preservation (12). Under the action of high-temperature working conditions, the inner side surface of the flue is mainly protected, and the erosion of high-temperature flue gas flow to the inner wall of the flue is reduced by spraying a castable and a wear-resistant alloy. And the smoke pressure relief is carried out by additionally arranging a relief valve. The Al-Si-Fe alloy wear-resistant coating is thermally sprayed, so that the surface performance is improved on the basis of keeping the excellent service performance of the matrix, and the service life of a flue is prolonged.

The furnace mouth section (1), the first flue section (2) and the second flue section (3) adopt forced circulation cooling structures, and the fourth flue section (5) adopts natural circulation cooling and is provided with forced circulation interfaces.

An inlet (1) of the furnace mouth section is connected with a gas outlet of the smelting reduction furnace, an outlet of a flue IV section (5) is connected with the settling chamber, the furnace mouth section and the smelting reduction furnace, the first flue section and the second flue section, and the IV flue section and the settling chamber are connected through metal expansion joints, and the furnace mouth section and the first flue section are connected through flanges.

The ascending section of the flue is provided with two pressure measuring points, and the descending section is provided with one pressure measuring point for tracking and measuring the pressure of the flue.

The inner walls of the furnace mouth section and the I section of the flue are knotted with refractory materials (6) which are phosphate-based binders, the thickness of the refractory materials is 50-100 mm, and the refractory materials are fixed by anchoring parts. Adopts slag-resistant and wear-resistant RSK series castable. The lining is fixed by adopting an anchoring piece and is used for supporting and fixing the refractory castable of a thinner lining body, so that the erosion of high-temperature flue gas to the inner walls of a furnace mouth section and a flue, particularly the position of flue gas impact, is reduced.

The outer surface of the flue pipe is provided with a heat insulation layer (12), the part of the heat insulation layer, which is in contact with the outer surface of the flue pipe, is a rock wool product, a protective layer is arranged outside the rock wool product, and the protective layer is galvanized iron sheet.

The forced circulation cooling structure is a film type wall tube panel structure.

And two bleeding valves (11) are arranged on the III section of the flue and used for pressure relief of the flue gas.

The first section of the flue and the second section of the flue are both provided with manholes (9) for people to enter and exit equipment so as to be convenient for installation, maintenance and safety inspection.

Further, a process for utilizing the waste heat of the vaporization cooling flue is provided, which comprises the following process steps:

(1) and generating a large amount of coal gas with high temperature, high heat value and carrying a large amount of furnace dust in a furnace top coal gas chamber of the smelting reduction furnace, wherein the temperature of the coal gas is 1600-1700 ℃, and the coal gas is continuously produced in the production process.

(2) The method prevents the wall surface of the evaporation cooling flue from slagging, and adopts the design that the flue is designed into a straight-through flue as far as possible, thereby reducing the retention time of high-temperature flue gas in the flue.

(3) The high-temperature coal gas is collected through the vaporization flue and is smelted the high-temperature coal gas of in-process and cool off it, the vaporization flue divide into furnace mouth section (1), I section (2) of flue, II section (3) of flue, III section (4) of flue, IV section (5) five parts of flue, the cross-section is circular, preceding four bibliographic categories divide and adopt forced circulation vaporization cooling, every part has all set up the hot water circulating pump, can realize forced cooling, last part is natural circulation and reserves forced circulation interface, I section (2) of flue, II section (3) of flue separate cooling, flue cooling tube water flow has been improved, the cooling effect has been increased, the life of flue has been prolonged. Each part is provided with a hot water circulating pump, so that forced cooling can be realized, the last part is natural circulation, a forced circulation interface is reserved, water production circulation is enhanced by adopting natural circulation, the volume of the evaporative cooling flue is reduced, and the compact structure is favorable for settling smoke dust and cleaning ash by vibration. And (3) reducing the temperature of the coal gas at the outlet of the evaporative cooling flue to 600-800 ℃, and then entering a cyclone dust collector for dust removal treatment. Not only makes full use of the physical sensible heat of the high-temperature coal gas, but also prolongs the service life of the equipment, and achieves the purposes of saving energy, reducing consumption and lowering production cost.

Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that changes, modifications, substitutions and alterations can be made in these embodiments without departing from the principles and spirit of the invention, the scope of which is defined in the appended claims and their equivalents.

Claims

1. The utility model provides a melting reduction furnace vaporization cooling flue, its characterized in that, vaporization cooling flue includes furnace mouth section (1), I section (2) of flue, II section (3) of flue, III section (4) of flue, IV section (5) of flue, and the vaporization cooling flue cross-section is circular, and the wall thickness of flue wall pipe is 10 ~ 50mm, and the inside and outside surface of flue scribbles rust-resistant primer, furnace mouth section and I section inner wall of flue knot refractory material (6), I section of flue, II section of flue, III section of flue and IV section of flue are at inner wall flue gas erosion position spraying abrasion-resistant alloy (10), and flue pipeline surface is equipped with heat preservation (12).

2. A smelting reduction furnace vaporization cooling flue according to claim 1, wherein the furnace mouth section (1), the first flue section (2) and the second flue section (3) adopt a forced circulation cooling structure, and the fourth flue section (5) adopts natural circulation cooling and is provided with a forced circulation interface.

3. The smelting reduction furnace vaporization cooling flue according to claim 1 or 2, wherein an inlet of the furnace mouth section (1) is connected with a coal gas outlet of the smelting reduction furnace, an outlet of the flue IV section (5) is connected with the settling chamber, the furnace mouth section and the smelting reduction furnace, the first flue section and the second flue section, and the fourth flue section and the settling chamber are connected through metal expansion joints, and the furnace mouth section and the first flue section are connected through flanges.

4. A smelting reduction furnace vaporization cooling flue according to claim 3, wherein the rising portion of the flue is provided with two pressure measuring points, and the falling portion is provided with one pressure measuring point for tracking and measuring the flue pressure.

5. The smelting reduction furnace vaporization cooling flue according to claim 4, wherein the fire-resistant material (6) is knotted to the inner walls of the furnace mouth section and the first flue section, and is made of phosphate-based binder, the thickness of the fire-resistant material is 50-100 mm, and the fire-resistant material is fixed by an anchoring member.

6. The smelting reduction furnace vaporization cooling flue according to claim 5, wherein an insulating layer (12) is provided on an outer surface of the flue pipe, a portion of the insulating layer contacting the outer surface of the flue pipe is a rock wool product, a protective layer is provided outside the rock wool product, and the protective layer is galvanized iron.

7. The smelting reduction furnace evaporative cooling flue of claim 6, wherein the forced circulation cooling structure is a membrane wall panel structure.

8. A smelting reduction furnace evaporative cooling flue as claimed in claim 7, wherein two bleeding valves (11) are provided in the third stage of the flue for pressure relief of flue gas.

9. A smelting reduction furnace evaporative cooling flue as claimed in claim 8, wherein the first and second sections of the flue are provided with manholes (9) for personnel to enter and exit the facility for installation, maintenance and safety inspection.